Precast rooms

ABSTRACT

Concrete rooms, each having an integrally cast top segment, consisting of a top panel and three sidewalls, and a precast floor segment, secured to the top segment during its integral casting, are stacked on top of one another to form a rigid structure of multiple floors. The rear ends of the rooms have integrally cast cantilevered overhangs such that when the rear ends of two stacks of rooms are positioned adjacent one another the cantilevered overhangs form floors and ceilings for the corridors defined by the space between the stacks. Each stack of rooms consists of an alternating arrangement of long and short rooms, each short room having a locking ridge at its forward end for locking into an opening formed across the forward end of a corresponding longer room.

United States Patent [72] Inventor Henry B. Zachry San Antonio, Tex.[21] Appl. No. 814,612 [22] Filed Apr.9, 1969 [45] Patented Aug.3, 1971[73] Assignee 11.13. Zachry Company San Antonio, Tex.

(54] PRECAST ROOMS 6Claims,2Drawlng Figs.

[52] U.S.C1 52/73, 52/79, 52/122, 52/236 [51} 1nt.Cl E0412 1/34, E04hH04 [50] Fieldoi'Search 52/79, 73, 234, 236, 237; 46/25, 19

[56] References Cited UNITED STATES PATENTS 2,691,291 10/1954 Henderson52/79X 3,292,327 12/1966 Van Der Lely.. 52/79 3,446,340 5/1969 Mullen52/403 1,362,069 12/1920 Witzel 52/745 3,162,863 12/1964 Wokas 52/793,468,081 9/1969 Saarinen 52/79 FOREIGN PATENTS 1,202,413 1959 France52/79 1,465,539 1966 France 52/236 766,840 1967 Canada 52/79 PrimaryExaminer-John E. Murtagh Attorney-Christie, Parker & Hale ABSTRACT:Concrete rooms, each having an integrally cast top segment, consistingof a top panel and three sidewalls, and a precast floor segment, securedto the top segment during its integral casting, are stacked on top ofone another to form a rigid structure of multiple floors. The rear endsof the rooms have integrally cast cantilevered overhangs such that whenthe rear ends of two stacks of rooms are positioned adjacent one anotherthe cantilevered overhangs form floors and ceilings for the corridorsdefined by the space between the stacks. Each stack of rooms consists ofan alternating arrangement of long and short rooms, each short roomhaving a locking ridge at its forward end for locking into an openingformed across the forward end of a corresponding longer room.

PATENTED AUG 31971 INVEN'IOR. HENRY B. z/vc m PRECAST ROOMS BACKGROUNDOF THE INVENTION This invention relates to building construction, andmore particularly to precast concrete rooms which are stacked on top ofone another to form a rigid structure.

System-building techniques, in which prefabricated structural units areassembled to form a building, are of major consequence in theconstruction industry. Precast concrete modules, used in theconstruction of hotels, office buildings, and the like, are especiallywell suited for this type of construction. The precast units arefabricated at a casting plant adjacent the construction site or at adistance therefrom. They are then lifted by cranes into position on topof one another and secured together to form a rigid structure.

At present, it is often required that a frame be provided for supportingthe concrete modules and for aligning them with respect to one another.Attempts to eliminate frames have generally been unsuccessful. Forexample, it has not been possible to accurately align a number ofmodules in the required configuration. Fastening of the modules to oneanother, using tie rods and the like, has also been less thansatisfactory and ordinarily has resulted in increased constructioncosts.

STATEMENT OF THE INVENTION This invention relates to a structural systemin which a number of precast concrete rooms, having load bearing walls,are stacked together to form a rigid structure. Each of the rooms has anintegrally formed top segment comprising a ceiling and sidewalls, withone side of the room being completely open. A precast concrete floor issecured to the top segment during integral casting thereof. The end of aunit opposite its open end has a cantilevered overhang which serves as aportion of a corridor adjoining such end, a corresponding overhang of asecond unit serving as the remaining portion of the corridor. Theconcrete room is precast to form an integral unit by an initial castingoperation to form the floor and a subsequent casting operation whereinthe ceiling and three sidewalls are simultaneously cured and secured tothe floor.

In the preferred form of the invention, the room is reinforced by anumber of steel-reinforcing bars embedded in the concrete structure andextending across the walls, floor and ceiling. Steel rods or cables canbe employed to prestress the concrete in three directions. The sidewallsmay have any number of openings cast in them for doors, windows,plumbing, air-conditioning ducts, and the like. For example, the openwall of the unit, ordinarily disposed at the outside surface of thestructure, can be relatively large for accommodating sliding glassdoors. Lifting loops project from the ceiling of the unit, the loopsbeing formed by the projecting portions of steel cables embedded in theconcrete.

The structural system preferably comprises the stacking of alternatelong and short room units. Each of the short units has a locking ridgeat its forward end. Each long unit has an opening adjacent its forwardend for receiving the locking ridge of a short unit placed on topthereof. The cantilevered overhang of each unit projects above thesurface of the top panel. A short unit can thereby be positioned on topof a long unit so that its rear end abuts the raised portion of the longunit's cantilevered overhang and so that its forward end locks in theopening of the long unit. As a result, the units can be stacked on topof one another without the need for a frame or supporting network.

The cantilevered overhangs of the precast units preferably have a numberof reinforcement rods embedded in the concrete and projecting outwardly.When adjacent rear ends of two units are aligned, the reinforcement rodsoverlap and are welded together. The openings between the overhangs arefilled with concrete, which is cast to complete formation of thecorridor. The completed closure thus defines both a floor for thecorridor above the aligned units and a ceiling for the corridor betweensuch units.

FIG. I is a perspective view ofa precast concrete unit ofthis invention;and

FIG. 2 is an elevation view of the precast concrete units.

l, structural system using DESCRIPTION OF THE PREFERRED EMBODIMENTSReferring to FIG. l, a room 10 includes a rectangular,

horizontal top panel or ceiling 12 formed of concrete and castintegrally with two elongated sidewalls M and a single, shorter end wall16. A conventional door opening (not shown) is formed in the end wall,the open side of the room opposite thereto having a sliding glass door18. Other openings (not shown) such as bathroom exhaust, windows, andair-conditioning ducts, may also be provided.

A plurality of reinforcing bars or cables 20 are disposed in the top,floor and walls of the room. Steel cables 22 are embedded in the wallsof the unit with their looped ends 24 projecting from the ceilingportion thereof, the loops serving as hoist connections for permittingthe units to be hoisted by a crane.

The rear end of the concrete unit, to be disposed toward the inside ofthe building under construction, has a cantilevered overhang 26projecting from its upper edge. The overhang is integrally cast with theceiling and three walls. Steel-reinforcing rods 28 are embedded in theoverhang and project therefrom along its three sides.

The forward end of the precast unit has a raised panel section 30 behindwhich is disposed an opening 32 in the roof of the unit. The opening isused to lock a shorter precast unit on top of the illustrated room, thetop unit fitting between the side 34 of the raised panel and the side 36of the projecting overhang 26. The open side of the front end of theprecast unit is preferably closed by slidable glass windows 38 and thedoor l8, which are disposed between the floor 40 and ceiling 12 adjacentthe opening 32 in the roof. A railing 42 is disposed across the width ofthe opening adjacent the ends of the sidewalls, defining a balcony areabetween the railing and the glass partition.

A number of horizontally extending steel rods 44 project from thesidewalls of the unit adjacent the opening of the roof, the steel rodssecuring on either side of the unit a steel plate 46. The steel plateand rods can be aligned with similar plates and rods on units spacedadjacent and on top of or below the illustrated unit.

FIG. 2 shows a rigid structure constructed in accordance with thestructural system of this invention. A long unit 48, supported on a base50, forms the first flloor of the structure. A short unit 52 is disposedon top of the long unit between the raised edge 36 of the cantileveredoverhang and the rear edge 34 of the raised panel 30 of the long unit.The short unit has a locking ridge 54, partially shown in dotted lines,which projects into the opening 32 of the long unit, such that the upperunit is securely mounted on the lower unit. Adjacent steel plates 46secured to the upper and lower units are welded together at theircontacting edges 56 to further secure the units. The rooms can be tiedtogether by weldments or resin systems and by prestressing of the walls,floors and roofs in three directions, using rods or cables. Neoprenepads or other flexible material 58 can be disposed between the rooms toobtain precise leveling of the stacks. A second stack of precast units(not shown) can be positioned adjacent the stacks shown in FIG. 2 andsecured at its forward end thereto by welding together of the steelreinforcing rods 44 projecting from the side plates 46. Brick-facedconcrete closure panels (not shown) which cover the space separatingadjacent units, are then secured to the reinforcement rods and steelplates of each adjoining unit to complete the outward side of thestructure. Removable closure panels (not shown) are disposed at theinner ends of the units. An integral cover or slab 60 can be disposedacross the tops of the adjacent stacks to complete the structure.Alternately, such integral cover or slab can be used as a floor for aprecast unit or the like having a larger surface area than that of theunits stacked below it.

The cantilevered overhangs 26 of two bottom units 47,48 are finished toprovide a ceiling 62 for the hallway between the lower units and a floor64 for the hallway running between the upper units 51,52. Thesteel-reinforcing cables 28 projecting from each overhang are weldedtogether and concrete is cast in such spaces using box forms.

In construction of a building using a structural system as in accordancewith this invention, a number of concrete modules are cast at a castingplant either adjacent the construction site or at a distance therefrom.lf cast at a distant plant, the modules can be easily moved by truck orthe like to the construction site. Each unit is completely finishedprior to its assembly in the structure. For example, heating andair-conditioning units, carpeting, electrical connections, and the like,are installed at the casting plant area. All furnishings going into therooms are likewise placed in the rooms before their movement from thecasting yard.

The precast units are readily lifted into position using a large cranehaving a hoisting platform for attachment to the four lifting loops ofthe unit. Before placing one unit in posi tion on top of another unit,leveling pads of resinous grout or the like are spread on top of theroom on which the unit is to be placed. The pads, typically of aboutifi-inch thickness, are set to establish grade so that each room can beleveled and plumbed with elimination of any cumulative error. Theresinous grout ordinarily develops a strength of about 4,000 p.s.i. infrom 30 minutes to about 2 hours. Prior to positioning of the room onthe leveling pads, a cement-sand grout layer, slightly thicker than aleveling pad, is placed around the top perimeter of the bottom roomunit. The next unit is thus positioned in full contact with the lowerunit, resting firmly on the leveling pads and grout bed.

In a preferred technique for erecting a building, using precast concretemodules substantially the same as those described in FIGS. 1 and 2, astack of modules is formed by alternating long and short units, eachpair of long and short units being locked together by a ridge of a shortunit and an opening of a long unit. That is, after proper positioning ofa long unit, a short unit is lifted into position with its rear endabutting the projecting edge of the cantilevered overhang of the longunit and with the projecting ridge of the short unit's opposite endlocking with the opening formed in the long unit. A similar stack ofalternating long and short units is aligned with the first stack withtheir rear ends positioned so as to form a corridor between the endwalls. A pair of such stacks can then be positioned adjacent the firstpair of stacks.

Preferably, the adjacent stacks are assembled so as to alternate longand short units across the face of the structure as well as verticalthereto. That is, when three stacks of modules are positioned adjacentone another, each unit of one length will have units of the oppositelength adjacent each of its opposing sidewalls. The resulting structuralsystem thereby can be rapidly constructed and is characterized byoverall rigidity.

lclaim:

l. A structural system comprising aplurality of precast concrete roomsstacked together to'form a rigid structure each room having a top panelintegrally formed with three sidewalls, at least one of the sidewallshaving an opening, and a floor secured to the sidewalls, the floor beingprecast. and secured to the walls simultaneously with integral castingofthe walls, the stacked rooms defining pairs of interlocking concreterooms of long and short lengths, the lower room being longer than theupper room and having an opening adjacent its forward end, the upperroom having a projecting ridge along its lower front edge, the ridgebeing adaptable for interlocking with the opening of the lower room.

2. The structural system of claim 1 wherein the building has both rowsand columns of alternating long and short rooms.

3. The structural system of claim 1 wherein each room has a verticallydisposed steel plate and horizontally projecting reinforcement rodssecured to the forward edge of each sidewall, such that an interlockingpair of units can be positioned to align the steel plates so that theycan be welded together to securely cou le each pair of units, thereinforcement rods being ahgna le with the reinforcement rods of adacent modules so that they can be welded together to secure adjacentstacks of units.

4. A building comprising a plurality of precast concrete rooms stackedtogether, each room including a floor, at least three load-bearingsidewalls integral with the floor, and a top panel integral with thesidewalls, each pair of stacked rooms having a cooperating floor and toppanel defining an interlocking interface with a projecting ridgeintegral with one room constructed to interlock with an opening in theother room so the two rooms form a rigid structure; and a verticallydisposed steel plate abutting a sidewall of each room, and horizontallyprojecting reinforcement rods embedded in each sidewall, the steelplates being aligned when the rooms are stacked together so that theplates can be welded together to securely couple the rooms, with thereinforcement rods of each room being arranged to align with thereinforcement rods of an adjacent room so the rods can be weldedtogether to secure adjacent stacks of rooms.

5. A building according to claim 4 wherein each room has a cantileveredoverhang integral with an edge of its respective top panel, eachoverhang including means for joining it with another room disposedadjacent to it to form a corridor between the adjacent rooms.

6. A building according to claim 4 wherein each interlocking pair ofstacked rooms defines a lower room and an upper room; and wherein theridge is integral with the bottom surface of the floor of the upper roomso as to project downwardly toward the lower room, and the opening isformed in the top panel of the lower room so that the ridge interlockswith the opening when the upper and lower rooms are stacked.

1. A structural system comprising a plurality of precast concrete roomsstacked together to form a rigid structure each room having a top panelintegrally formed with three sidewalls, at least one of the sidewallshaving an opening, and a floor secured to the sidewalls, the floor beingprecast and secured to the walls simultaneously with integral casting ofthe walls, the stacked rooms defining pairs of interlocking concreterooms of long and short lengths, the lower room being longer than theupper room and having an opening adjacent its forward end, the upperroom having a projecting ridge along its lower front edge, the ridgebeing adaptable for interlocking with the opening of the lower room. 2.The structural system of claim 1 wherein the building has both rows andcolumns of alternating long and short rooms.
 3. The structural system ofclaim 1 wherein each room has a vertically disposed steel plate andhorizontally projecting reinforcement rods secured to the forward edgeof each sidewall, such that an interlocking pair of units can bepositioned to align the steel plates so that they can be welded togetherto securely couple each pair of units, the reinforcement rods beingalignable with the reinforcement rods of adjacent modules so that theycan be welded together to secure adjacent stacks of units.
 4. A buildingcomprising a plurality of precast concrete rooms stacked together, eachroom including a floor, at least three load-bearing sidewalls integralwith the floor, and a top panel integral with the sidewalls, each pairof stacked rooms having a cooperating floor and top panel defining aninterlocking interface with a projecting ridge integral with one roomconstructed to interlock with an opening in the other room so the tworooms form a rigid structure; and a vertically disposed steel plateabutting a sidewall of each room, and horizontally projectingreinforcement rods embedded in each sidewall, the steel plates beingaligned when the rooms are stacked together so that the plates can bewelded together to securely couple the rooms, with the reinforcementrods of each room being arranged to align with the reinforcement rods ofan adjacent room so the rods can be welded together to secure adjacentstacks of rooms.
 5. A building according to claim 4 wherein each roomhas a cantilevered overhang integral with an edge of its respective toppanel, each overhang including means for joining it with another roomdisposed adjacent to it to form a corridor between the adjacent rooms.6. A building according to claim 4 wherein each interlocking pair ofstacked rooms defines a lower room and an upper room; and wherein theridge is integral with the bottom surface of the floor of the upper roomso as to project downwardly toward the lower room, and the opening isformed in the top panel of the lower room so that the ridge interlockswith the opening when the upper and lower rooms are stacked.